As is known in the art a local area network is a communications network that interconnects of a variety of data communicating devices generally within a physically limited area. Points in a network where communication service is provided, used or where communication channels are interconnected are generally referred to as network nodes or simply nodes. Connected to each of the nodes are devices, generally referred to as stations, which wish to receive and transmit data. The network nodes may be connected using so-called internodal links. Thus, the stations may receive and transmit data via the network nodes and internodal links.
The internodal links between such nodes may be provided as so called point-to-point, multi-point or store-and-forward links. A point-to-point link is a transmission facility that connects only two nodes. A point-to-point transmission facility allows many nodes to communicate with a common node through non-interfering channels. One problem in some point-to-point systems however is that such systems have an internodal acoustic telemetry channel which is a broadcast channel to which all stations coupled to the network have access. This requires a careful orchestration of data packet transmission activity to minimize interference between two packet streams routed through common nodes. Thus, interference from non-neighboring nodes may result.
The so-called multi-point or multi-drop facilities provides service to many nodes that share access to the same transmission facility.
In so called store-and-forward systems, a message from one station is received at a computer acting as a switch and is stored there. After the computer has determined a destination address and an available communication circuit, the message is forwarded to the destination. This method may also be referred to as message switching. In some applications the length of the transmissions handled is limited by breaking up long messages into packets and thus is generally referred to as packet switching.
As is also known, local area networks generally have a set of rules for communicating between nodes generally referred to as a network protocol. In formulating the protocols, the network nodes are generally assumed to have an infinite energy supply and the protocols fail to minimize the number of retransmissions which occur in the network. Furthermore, the round trip propagation time between nodes is generally not a concern in such local area networks. Thus, network protocols are generally formulated to maximize network throughput and minimize expected delay.
In some applications however it may be desirable to have packet transmissions which are power efficient and which minimize the number of retransmissions in a network. This is particularly true in those applications where the network nodes may be provided having non-replaceable non-rechargeable power supplies.